273
FXUS66 KEKA 222204
AFDEKA

AREA FORECAST DISCUSSION
National Weather Service Eureka CA
304 PM PDT Sun Sep 22 2024

.SYNOPSIS...Warm and dry conditions will continue to gradually
settle in today with weakening north winds along the coast. Heat
will peak early this week with above average temperatures pushing
out even along the coast.


&&

.DISCUSSION...High pressure continues promoting dry and warm
pattern across Northern California through Tuesday. Mostly clear
skies prevail across the area, except along the Mendocino Coast
where a shallow marine layer persist. Breezy north-northwesterly
winds will occur along nearshore and along Eel River Valley into
early evening. Overnight temperatures are expected to cool into
low 50`s, while a strong thermal belts will maintained upper
elevation lows in the 60s.

The low-level airmass will continue to warm on Monday (850mb
temperatures ranging from 23 to 26), with high temperatures
between 100 to 105F in the hottest interior valleys. The ridge
will begin to slowly shift eastward on Tuesday, however similar
temperatures. These temperatures will be 10 to 15 degrees above
normal, promoting Moderate Heat Risk Monday and Tuesday across the
interior. This level of heat affects most individuals sensitive
to heat, especially those without effective cooling and/or
adequate hydration.This level of heat affects most individuals
sensitive to heat, especially those without effective cooling
and/or adequate hydration. Even the coastal areas are anticipated
to warm up above normal with high in the 70`s as northerly winds
weaken, especially along the North Coast. Confidence is not high
for the Mendocino Coast due to the persistent shallow marine
layer.

High pressure will begin to breakdown and slowly shift eastward
on Tuesday as an upper level trough approaches the Pacific
Northwest. Meanwhile, a cutoff located offshore southern
California will drift northward parallel to the coast before being
absorbed by the upstream trough late Tuesday night. The main
trough will move across the Pacific Northwest on Wednesday,
followed by another trough around Thursday. Overall for our area
not much chances of precipitation is expected, other than some
light drizzle along the coast. The primary affect from these
transient shortwave troughs will be to knock temperatures down to
around seasonal or slightly below seasonal averages; highs from
upper 88 to 91F. /ZVS


&&

.AVIATION...Clear skies are forecast to continue at all terminals
through this TAF period. Stratus and fog will continue to result in
LIFR cigs and vsbys along the Mendocino coast tonight through
Monday. Only patchy stratus and fog is expected around Humboldt
Bay/Eel Delta with less than a 20% chance for LIFR at KACV from 14Z
to 18Z Monday. Very marginal low level wind shear remains possible
at coastal terminals after surface winds decouple and east winds to
25kt develop a thousand feet above mean sea level this evening. DB


&&

.MARINE...Near gale conditions with occasional gusts to around 35 kt
and large steep northerly wind waves near 10 feet are forecast to
continue in the outer waters through Monday. Steep wind waves will
also propagate into the inner waters through Monday, primarily in
the northern inners. Northerly conditions will ease Monday night and
then lay down more substantially on Tuesday and Wednesday as the
thermal trough weakens and shifts inland. A series of mid period NW
swell will build early next week, peaking around to around 8 ft on
Wed. Potential for gale force northerlies and large steep waves
over 10 feet will increase Fri-Sat. DB


&&

.FIRE WEATHER...(From previous discussion) Building heat and high
pressure this week will continue to enhance fire weather
conditions with daytime highs in the mid 90s to low 100s and
minimum RH in the teens. Overnight recoveries will continue to be
poor at mid and high elevations with recoveries of 20 to 40
percent though Tuesday morning. Except for some enhanced north
wind right along shore and channeled along the Eel river valley
Sunday, daytime winds will be mostly gentle and terrain driven.
Low pressure off the central California coast combined with high
pressure will help enhance night time northeast flow at high
elevations. Northeast wind gusting up to 25 mph should be expected
a high elevations late each night early this week. This risk will
be focused in the usual areas of Del Norte and Lake Counties but
will also include the usually calmer ridges of Southern Humboldt
and northern Mendocino Counties. Generally more mild conditions
will build in late in the week with increasing marine influence.
/JHW


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
None.
NORTHWEST CALIFORNIA COASTAL WATERS...
     Small Craft Advisory until 9 AM PDT Monday for PZZ450-455.

     Small Craft Advisory until 9 AM PDT Tuesday for PZZ470.

     Small Craft Advisory until 3 AM PDT Tuesday for PZZ475.

&&

$$

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